Lead-in for devices with a quartz bulb



June 24, 1969 E. K. ZIL BERMAN ETAL 3,452,322

LEAD-IN FOR DEVICES WITH A QUARTZ BULB Sheet Filed July 12; 1967 June 24, 1969 E. K. ZILBERMAN ET AL 3,452,322

LEAD-IN FOR DEVICES WITH A QUARTZ BULB Filed July 12. 1967 Sheet 3 of 2 United States Patent 3,452,322 LEAD-IN FOR DEVICES WITH A QUARTZ BULB Evgeny Konstantinovich Zilbermau, Smoleuski, and Erik Pavlovich Morin, Riga, U.S.S.R., assignors to Rizhsky Elektrolampovy Zavod, Riga, U.S.S.R.

Filed July 12, 1967, Ser. No. 652,880 Int. Cl. H01r 33/74 U.S. Cl. 339144 4 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to the lead-in of devices with a quartz bulb and, in particular, to the lead-in of high-intensity quartz lamps.

In present-day practice, a vacuum seal of the metallic lead-in and the quartz bulb of light sources and other devices with a quartz bulb is provided by the use of intermediate glass components having different coefi'ipients of expansion or, alternatively, by sealing in molybdenum foil having a thickness of up to 50 micron, the foil forming a part of the lead-in. The manufacture of lamps rated over 100 a. and provided with such a seal presents cofi siderable difficulties and requires a high class of workmanship (see French Patent 'No. 1,120,475, Lamp With a Foil Seal-in, Osram lamp with intermediate glass components, type XB O 1600 W/P lamp).

Known in the art are, also, high-intensity quartz arc lamps, wherein a hermetically-sealed flanged joint is provided between the metallic lead-in and a quartz stem by the insertion of an intermediate lead sealing gasket. Such a lead-in requires cooling by a flow of water and, consequently, is of a complicated design, inconvenient in use and of limited application.

An object of the present invention is to simplify the construction of the lead-in, eliminate the necessity of cooling the lead-in by a flow of water and, thus provide a device free of the above-cited disadvantages.

In accordance with the invention, the above and other objects are attained by providing the lead-in with a sealing gasket in the form of a copper ring that is pressed against the end surface of the quartz stem by means of special springs.

According to another object of the invention, the above copper ring is compressed by special ties arranged parallel to the longitudinal axis of the lead-in.

It is recommended to taper the end surface of the copper ring that is in direct contact with the end surface of the quartz stem to an angle of 60 to 90.

Both end surfaces of the copper ring may be tapered to an angle of 60 to 90.

The invention, will further be described by way of example with reference to the accompanying drawing wherein:

FIG. 1 shows in elevation, and partly broken away in section, an extra-high pressure high-intensity xenonvapor arc lamp; and

FIG. 2 shows in section the lead-in of the extra-high 3,452,322 Patented June 24, 1969 pressure high-intensity xenon-vapor arc lamp according to the present invention.

The extra-high pressure quartz lamp comprises lead-in l, 2 (see FIGS. 1 and 2) and quartz bulb 3.

Lead-in 1 (see FIGS. 1 and 2) consists of a hermetically-sealed flanged joint of current-collector 4 (see FIG. 2) and quartz stem 5. Thickened section 5' of quartz stem 5 is secured to flange 7 through cement layer 6 which prevents inclination and diminishes the pressure applied to the quartz stem during assembly of lead-in 1. Metal rod 8 supplying the current to anode 9 (see FIG. 1) is passed through a longitudinal base 10 (see FIG. 2) in stem 5, the free end 11 of the rod being press-fitted in current-collector 4. Recess 13 with a tapered annular projection '14 is bored in lower part 13 of current collector 4. Recess 13 houses copper sealing ring 15, the flat end surface of which is forced against tapered annular projection 14 of recess 13, whereas section 16 tapered to an angle of 60 to is forced against flat end surface 17 of the thickened section of stem 5. Both end surfaces of copper ring 15 may be tapered. Two dished springs 18, washer 19 and flange 20 into which hollow screw 21 is driven are fixed to the outer surface of current collector 4. Flanges 7, 20 and washer -19 have respective grooves 22, 23, 24 containing ties 25.

When hollow screw 21 is screwed into flange 20, ties 25 limit the displacement of flanges 7, 20 and the applied force is transmitted to lower part 12 of currentcollector 4 and to copper sealing ring 15 through disk springs 18. Tapered section 16 of sealing ring 15 readily acquires the shape of the micro-relief of the end surface of quartz stem 5 with which it is in contact and, consequently, is fitted closely to it, whereas tapered projecion 14 of the annular recess of current-collector 4 cuts into flat end surface of sealing ring 15. As a result, a reliable hermetically-sealed joint ensuring not only an adequate vacuum tightness of the lead-in but capable also of withstanding a pressure of up to one hundred atmospheres is easily provided between metallic current-collector 4 and quartz stem 5 at the application of a comparatively small mechanical force to the latter. Disk springs 18 permanently force current collector 4 against sealing ring 15 and sealing ring 15 against quartz stem 5, thus preventing impairment of the vacuum seal at uneven thermal expansion of the seal components on the lead-in being heated during the operation of the lamp.

Metallic cap 26 is fitted for making it easier to apply cement layer 6 and for ensuring that the thickened sections 5' of stem 5 are of equal lengths.

The herein described lead-in has been used for 3 kw. e xtra-high pressure xenon-vapor arc lamps having a working current of to A. and a gas pressure of 25 to 30 atm. at operation of the lamp and, likewise, for 1 kw. lamps having a working current of 45 to 50 A. and gas pressure of 25 to 30 atm.

Employment of the present invention makes it possible to reduce the size of the xenon arc lamp and considerably simplify the technology of their manufacture.

What is claimed is:

1. A lead-in for devices with a quartz bulb and, in particular, for high-intensity quartz lamps comprising: a current-collector; a hollow quartz stem; a sealing gasket in the form of a copper ring placed between the end surafce of the above-mentioned current-collector and the end surface of the above-mentioned quartz stem; and a spring mounted for pressing the sealing gasket the end surface of the quartz stem.

A lead-in rdi to claim .1. wherein m mm...

ring is compressed by means of ties arranged parallel to the longitudinal axis of the current-collector;

3. A lead-in according to claim 1, wherein the end surface of the copper ring that is in direct contact with the end surface of the quartz stem is provided with a sharp annular rim tapered to an angle of 60 to 90.

4. A lead-in according to claim 1, wherein at least one end surface of the copper ring is provided with a sharp annular rim tapered to an angle of 60 to 90.

4 References Cited UNITED STATES PATENTS 3,200,366 8/1965 Stuart 33994 X 3,256,383 6/ 1966. Sasorov 17417.07 3,351,803 11/1967 Kearney 313-318 X 3,363,219 1/1968 Hubbard et a1. 339-95 RICHARD MOORE, Primary Examiner. 

